CASPER in the Machine: Insights into Character Variety in LLM-Generated Stories

Anneliese Brei, Abhisheik Sharma, Nicholas Sanaie, Lu Wang, Snigdha Chaturvedi


Abstract
As LLM-generated text is increasingly used, especially in fictional domains, we explore how much LLM-generated stories differ from human-written stories. In this work, we focus on characters. We borrow definitions from narratology to analyze 8 intricate category-pairs of character, such as stylization and wholeness. These category-pairs consider more than just basic characteristics. They assess how characters are portrayed within their stories. After automatically inferring categories of characters within both LLM and human-written stories, we compare and contrast these two sets of stories. We consider the following overarching questions: (1) Do LLMs and human-written stories have similar characters? and (2) Do LLMs generate stories with a variety of characters? Our analysis includes research questions that focus on stories generated by popular LLMs and recently published human-written stories. We describe a number of interesting similarities, differences and key takeaways.
Anthology ID:
2026.acl-long.675
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
14815–14840
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.675/
DOI:
Bibkey:
Cite (ACL):
Anneliese Brei, Abhisheik Sharma, Nicholas Sanaie, Lu Wang, and Snigdha Chaturvedi. 2026. CASPER in the Machine: Insights into Character Variety in LLM-Generated Stories. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 14815–14840, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
CASPER in the Machine: Insights into Character Variety in LLM-Generated Stories (Brei et al., ACL 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.675.pdf
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 2026.acl-long.675.checklist.pdf